spirobacterium

from The Collaborative International Dictionary of English v.0.48

Spirobacteria \Spi`ro*bac*te"ri*a\, n. pl.; sing.
   {Spirobacterium}. [NL. See 4th {Spire}, and {Bacterium}.]
   (Biol.)
   See the Note under {Microbacteria}.
   [1913 Webster] Spirochaeta